mutation.yml

name: Mutation

# Mutation testing (StrykerJS) — issue #1028.
#
# WARNING, not a PR gate (issue #1056): this workflow runs weekly + on demand
# only — never on pull_request — so it can NEVER block a PR or merge. The
# per-package Stryker configs set a `thresholds.break` floor (libs/*/stryker.conf.mjs,
# ~6 pts under the CI baseline); a real mutation-score regression makes this
# weekly run go red (a visible signal in the Actions tab), instead of vanishing
# into a green check.
#
# Mutation runs are slow (a full pass mutates every source file and re-runs
# the suite per mutant), which is why this is off the per-PR hot path.

permissions:
  contents: read

on:
  workflow_dispatch:
  schedule:
    # Weekly, Monday 06:00 UTC.
    - cron: "0 6 * * 1"

jobs:
  mutation:
    runs-on: ubuntu-latest
    strategy:
      fail-fast: false
      matrix:
        package:
          [
            act,
            act-pg,
            act-sqlite,
            act-tck,
            act-http,
            act-crypto,
            act-patch,
            act-ops,
          ]
    services:
      # Always provisioned; only @rotorsoft/act-pg's specs connect to it
      # (port 5431, mirroring the unit-test CI job in ci-cd.yml).
      postgres:
        image: postgres:18-alpine
        env:
          POSTGRES_PASSWORD: postgres
        options: >-
          --health-cmd pg_isready
          --health-interval 10s
          --health-timeout 5s
          --health-retries 5
        ports:
          - 5431:5432
    steps:
      - uses: actions/checkout@v7
      - uses: pnpm/action-setup@v6
        with:
          run_install: false
      - uses: actions/setup-node@v7
        with:
          node-version: 22.23.2
          cache: "pnpm"

      - run: pnpm install

      - name: Run mutation testing (${{ matrix.package }})
        run: pnpm --filter @rotorsoft/${{ matrix.package }} run mutation

      # Compute the mutation score from Stryker's JSON report and append it
      # to the run summary. Score = (Killed + Timeout) / (Killed + Timeout +
      # Survived + NoCoverage) — the standard StrykerJS mutation score.
      - name: Publish mutation score (${{ matrix.package }})
        if: always()
        run: |
          node -e '
            const fs = require("fs");
            const pkg = "${{ matrix.package }}";
            const f = `libs/${pkg}/reports/mutation/mutation.json`;
            const out = process.env.GITHUB_STEP_SUMMARY;
            if (!fs.existsSync(f)) {
              fs.appendFileSync(out, `## Mutation — ${pkg}\n\nNo report produced.\n\n`);
              process.exit(0);
            }
            const report = JSON.parse(fs.readFileSync(f, "utf8"));
            const counts = {};
            for (const file of Object.values(report.files ?? {})) {
              for (const m of file.mutants ?? []) {
                counts[m.status] = (counts[m.status] ?? 0) + 1;
              }
            }
            const detected = (counts.Killed ?? 0) + (counts.Timeout ?? 0);
            const undetected = (counts.Survived ?? 0) + (counts.NoCoverage ?? 0);
            const valid = detected + undetected;
            const score = valid ? ((detected / valid) * 100).toFixed(2) : "n/a";
            const md = [
              `## Mutation — ${pkg}`,
              "",
              `**Mutation score: ${score}%** (non-blocking baseline)`,
              "",
              "| Status | Count |",
              "|---|---:|",
              ...Object.entries(counts).map(([k, v]) => `| ${k} | ${v} |`),
              "",
            ].join("\n");
            fs.appendFileSync(out, md + "\n");
          '

      - name: Upload mutation report (${{ matrix.package }})
        if: always()
        uses: actions/upload-artifact@v7
        with:
          name: mutation-report-${{ matrix.package }}
          path: libs/${{ matrix.package }}/reports/mutation/
          if-no-files-found: ignore